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(Speeimens.)

J. G. PENNYOUIGK.-

WINDOW GLASS.

N0. 312,290. Patented Feb. 17, 1885.

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fizz 7 UNITED STATES PATENT OFFICE.

JAMES G. PENNYOUIOK, OF NEYV YORK, N. Y.

WINDOW-GLASS.

SPECIFICATION forming part of Letters Patent No. 312,290, dated February17, 1885.

(Specimens) T 0 all whom it may concern:

Be it known that I, J nuns G. PENNYOUIOK, a citizen of Great Britain, atpresent residing in New York city, State of New York, have invent-ed anew and useful Improvement in XVindow-Glass, of which the following is aspecification.

The nature of my invention consists in the construction ofwindow-glass,whereby the reflection of the light into the room isconsiderably increased without increasing the size of the window.

In the accompanying dra\vings,Figurc I represents a front view of myimproved windowglass. Fig. II is a side view of the same.

A represents my improved window-glass, one side of which is madeperfectly straight, and the other side is provided with ribs orprojections at. These ribs or projections a extend only within one-halfof an inch or more of the edges of the surface, leaving a space, 0, ontop, bottom, and sides of the sheet of glass, flat or straight on bothsides, for fastening the same into the window-frame in the usual manner.The ribs or projections a are made triangular in section, the topsurfaces, 2, of each being parallel to each other,and nearly square withthe body of the glass sheet, and the front surfaces, 3, being diagonal,running from the outer edge of the top surface, 2, to the inner edge ofthe surface of the lower rib, or to the body of the glass sheet A. Bythis construction of window-glass about double the quan tity ofreflection or illumination of the plain window-glass of same size willbe obtained, and will obviate the necessity of ground or opaque glass(whereby the admission of light is still more obstructed) in placeswhere it is not desirable to have a view into the room from the outside.

I am aware that it is not broadly new to providewindowglass withreflecting-ridges; but the ridges heretofore employed have been formedwith similarlyinclined or angular side surfaces. The effect of ridgesthus formed is to concentrate the light at the point of meeting of theangles. My improvement comprehends only a ridge one of whose sides is atpractically a right angle to the body of the glass,while the other sideis inclined at an angle approximating forty -iive degrees. The effect ofthis form of reflector is to thoroughly diffuse the light, which firstsilvers the plane surface of the ridge and is then reflected from theinclined surface. Thus I obtain a mirror-like reflection and diffusionof light unattainable with a reflector of inverted pyramidal form.

Vhat I claim as inyinvention, and desire to secure by Letters Patent, is

As a new article of manufacture, a window glass one side of which has aplane surface, while the opposite side is formed with a series of ribs,each of which is formed on one side with a surface at practically aright angle to the body of the glass, while its opposite side isinclined at less than a right angle, substantially as set forth.

JAMES G. PENNYOUIOK.

\Vi tn css es:

HENRY E. RouDER, J. B. Nouns.

